Pituitary tumours: TSH-secreting adenomas.

Thyrotropin-secreting pituitary adenomas (TSHomas) are a rare cause of hyperthyroidism and account for less than 2% of all pituitary adenomas. In the last years, the diagnosis has been facilitated by the routine use of ultra-sensitive TSH immunometric assays. Failure to recognise the presence of a TSHoma may result in dramatic consequences, such as improper thyroid ablation that may cause the pituitary tumour volume to further expand.

Impact of resistance to thyroid hormone on the cardiovascular system in adults.

Background: The clinical manifestations of resistance to thyroid hormone (RTH) are highly variable, and the impact of RTH on the cardiovascular system has been poorly investigated.

Aim: The objective of the study was to evaluate the cardiovascular characteristics of 16 untreated and asymptomatic patients with RTH compared with 16 euthyroid healthy controls to define the cardiovascular involvement in RTH syndrome.

Patients And Methods: Sixteen untreated and asymptomatic RTH patients (eight males; aged 33 +/- 12 yr, range 21-45 yr) and 16 controls (nine males; aged 33 +/- 5 yr, range 24-42 yr) were enrolled.

A novel tyrosine-kinase selective inhibitor, sunitinib, induces transient hypothyroidism by blocking iodine uptake.

Context: Sunitinib (sunitinib malate; SU11248; Sutent; Pfizer Inc., New York, NY) is a multitarget inhibitor of tyrosine kinases for the treatment of some human cancers. A myxedematous coma in a patient treated with sunitinib for a gastrointestinal stromal tumor was unexpectedly observed.

Thyroid scintigraphy and perchlorate test after recombinant human TSH: a new tool for the differential diagnosis of congenital hypothyroidism during infancy.

Purpose: Prompt initiation of L-thyroxine therapy in neonates with congenital hypothyroidism (CH) often prevents the performance of functional studies. Aetiological diagnosis is thus postponed until after infancy, when the required investigations are performed after L-thyroxine withdrawal. The aim of this study was to verify the efficacy and safety of new protocols for rhTSH (Thyrogen) testing during L-thyroxine replacement in the differential diagnosis of CH.

Syndromes of hormone resistance in the hypothalamic-pituitary-thyroid axis.

Forty years have elapsed since the first description of a syndrome of resistance in the hypothalamic-pituitary-thyroid axis, i.e., resistance to thyroid hormone action.

TBG deficiency: description of two novel mutations associated with complete TBG deficiency and review of the literature.

Thyroxine-binding globulin (TBG) is the main thyroid hormone transport protein in serum. Inherited TBG defects lead to a complete (TBG-CD) or a partial (TBG-PD) deficiency and have a diagenic transmission, being clinically fully expressed only in hemizygous males and in homozygous females. In the present study, seven patients from two unrelated families with TBG-CD were studied and two novel TBG mutations were documented.

Total iodide organification defect: clinical and molecular characterization of an Italian family.

Thyroid peroxidase (TPO) deficiency is frequently involved in total iodide organification defects (TIOD). According to the recessive mode of inheritance, mutations are found in homozygous or in compound heterozygous states. However, a single heterozygous TPO mutation is reported in a high percentage (approximately 20%) of patients with typical TIOD phenotype.

Radioiodine treatment of non-toxic multinodular goitre: effects of combination with lithium.

Purpose: This study aimed to evaluate the effects of radioiodine ((131)I), alone or in combination with lithium, on thyroid volume and the prevention of radioiodine-induced thyrotoxicosis. This is the first clinical trial including only patients with multinodular goitre, normal TSH values and negative anti-thyroid auto-antibodies at baseline.

Methods: Eighty consecutive patients were randomised to receive (131)I plus lithium (group I+L) or (131)I alone (group I).

Different responses to chronic somatostatin analogues in patients with central hyperthyroidism.

Objective: Central hyperthyroidism is mainly due to two different causes, TSH-secreting pituitary adenoma (TSH-oma) and resistance to thyroid hormone in its pituitary variant, i.e. patients presenting with signs and symptoms of hyperthyroidism (PRTH).

BRAF mutations in an Italian cohort of thyroid cancers.

Objective: Recently, a somatic point mutation of the BRAF gene (V599E) has been identified as the most common genetic event in papillary thyroid carcinoma (PTC) with a variable frequency (about 25-70%) in different series from USA, Japan, Portugal and Ukraine.

Design: In the present study, the genetic analysis of BRAF in an Italian cohort of 65 thyroid tumours with corresponding normal tissues and 21 thyroid benign disorders is reported.

Methods: For BRAF analysis, the somatic DNA was PCR amplified by means of specific intronic primers and PCR products were directly sequenced.

Recombinant human TSH testing is a valuable tool for differential diagnosis of congenital hypothyroidism during L-thyroxine replacement.

Objective: The differential diagnosis of congenital hypothyroidism (CH) is aimed to distinguish transitory from permanent forms, to optimize L-thyroxine (L-T4) therapy to replacement or TSH-suppressive regimens, and to reach accurate definition of the clinical and biochemical phenotype for subsequent genetic investigations and counselling. Therefore, L-T4 therapy is presently withdrawn in most instances and investigations are performed in a disturbing hypothyroid state.

Design: The availability of recombinant human TSH (rhTSH) prompted us to assess its efficacy in the differential diagnosis of CH during L-T4 therapy.

Serum activin A levels in different thyroid disorders.

Activin A belongs to the transforming growth factor-beta superfamily that exerts a wide range of biologic activities on cellular proliferation and differentiation. Although it was suggested that gonadal tissue is the primary site of activin production, several extragonadal sources have subsequently been identified, including human thyrocytes. The goal of the present study was to evaluate serum activin A levels in a series of patients with different thyroid disorders during the active state of the diseases and after recovery.

Highly sensitive serum thyroglobulin and circulating thyroglobulin mRNA evaluations in the management of patients with differentiated thyroid cancer in apparent remission.

We studied the potential role of innovative diagnostic tools for the management of patients with differentiated thyroid cancer (DTC). Several methods for the detection of the tumor marker thyroglobulin (Tg) have been employed in 36 patients in apparent remission at the moment of the study. All patients had negative anti-Tg antibodies and were evaluated during L-T(4) suppressive therapy before and after stimulation with recombinant human TSH (rhTSH).

Differential diagnosis between Pendred and pseudo-Pendred syndromes: clinical, radiologic, and molecular studies.

The disease gene for Pendred syndrome has been recently characterized and named PDS. It codes for a transmembrane protein called pendrin, which is highly expressed at the apical surface of the thyroid cell and functions as a transporter of chloride and iodide. Pendrin is also expressed at the inner ear level, where it appears to be involved in the maintenance of the endolymph homeostasis in the membranous labyrinth, and in the kidney, where it mediates chloride-formate exchange and bicarbonate secretion.